PDP driving device and method

ABSTRACT

In a PDP driving circuit, first and second inductors are coupled to a panel capacitor. The driving circuit stores a first energy in the first inductor through a current in the first direction while the voltage at the panel capacitor is maintained to be a first voltage, and uses the first energy and resonance between the panel capacitor and the first inductor to reduce the voltage at the panel capacitor to a second voltage. Next, the driving circuit maintains the voltage at the panel capacitor to be the second voltage, recovers the energy remaining in the first inductor, stores a second energy in a second inductor through a current in the second direction, and uses the energy stored in the second inductor to increase the voltage at the panel capacitor to the first voltage. Therefore, rising and falling time of the voltage at the panel capacitor is shortened, and zero-voltage switching is possible when the driving circuit has a parasitic component.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/373,605, filed Feb. 24, 2003 now U.S. Pat. No. 6,924,779, whichclaims priority to and the benefit of Korea Patent Applications No.2002-14480 filed on Mar. 18, 2002 and No. 2002-18266 filed on Apr. 3,2002 in the Korean Intellectual Property Office, priority of which arehereby claimed.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a device and method for driving aplasma display panel (PDP). More specifically, the present inventionrelates to a PDP sustain-discharge circuit or an address drivingcircuit.

(b) Description of the Related Art

In general, a PDP is a flat plate display for displaying characters orimages using plasma generated by gas discharge. Pixels ranging fromhundreds of thousands to more than millions are arranged in a matrixform according to the size of the PDP. PDPs are categorized as directcurrent (DC) PDPs and alternating current (AC) PDPs according topatterns of the waveforms of applied driving voltages and structures ofdischarge cells.

Current directly flows in discharge spaces while a voltage is suppliedto the DC PDP, because electrodes of the DC PDP are exposed to thedischarge spaces. Therefore, a resistor for restricting the current mustbe provided to the DC PDP. On the other hand, in the case of the AC PDP,the current is restricted due to the natural formation of a capacitancecomponent because a dielectric layer covers the electrodes. The AC PDPhas a longer life than the DC PDP, since the electrodes are protectedagainst shock caused by ions during discharge.

In general, a method for driving the AC PDP includes a reset period, anaddressing period, a sustain period, and an erase period.

In the reset period, the states of the respective cells are reset inorder to smoothly address the cells. In the addressing period, the cellsthat are turned on and the cells that are not turned on in a panel areselected, and wall charges are accumulated to the cells that are turnedon (i.e., the addressed cells). In the sustain period, discharge isperformed in order to actually display pictures on the addressed cells.In the erase period, the wall charges of the cells are reduced tothereby terminate sustain-discharge.

In the AC PDP, since a panel between an address electrode, a sustainelectrode, and a scan electrode operates as a capacitive load, it isgenerally referred to as a panel capacitor. Reactive power is requiredin order to apply waveforms for the addressing or the sustain-dischargebecause of capacitance of the panel capacitor. A circuit for recoveringand re-using the reactive power is referred to as a power recoverycircuit. L. F. Weber discloses the power recovery circuits in the U.S.Pat. Nos. 4,866,349 and 5,081,400.

However, the conventional power recovery circuit only uses resonancebetween a panel capacitor and an inductor coupled to the panelcapacitor, and it normally operates only when a power recovery capacitoris charged with a voltage corresponding to half external power. Sincethe conventional power recovery circuit has a loss generated fromitself, such as a switch's conduction loss and switching loss, duringthe recovery process it fails to recover the entire energy. Accordingly,since a panel voltage may not be increased or decreased to a desiredvoltage level, switches problematically perform hard switching tothereby generate power loss, and rising time and falling time of thepanel voltage becomes longer.

SUMMARY OF THE INVENTION

In accordance with the present invention a PDP driving circuit for powerrecovery is provided. Rising time and falling time of the panel voltageare reduced, and zero-voltage switching is executed. The presentinvention stores energy in an inductor, and uses the stored energy tovary the panel voltage.

In one aspect of the present invention, a device for driving a PDP, thePDP having a plurality of address electrodes, scan electrodes, sustainelectrodes, and panel capacitors each formed between the address, scan,and sustain electrodes, includes: first and second capacitors coupled inseries between first and second power sources for respectively providingfirst and second voltages; first and second switches coupled in parallelto a point where the first and second capacitors meet; third and fourthswitches coupled in series between the first and second power sources, apoint where the third and fourth switches meet being coupled to thepanel capacitor; and first and second inductors respectively coupledbetween the first switch and a point where the third and fourth switchesmeet, and between the second switch and the point where the third andfourth switches meet.

The device further includes: a fifth switch coupled between the firstinductor and the second power source; and a sixth switch coupled betweenthe first power source and the first inductor.

In another aspect of the present invention, a device for driving a PDP,the PDP having a plurality of address electrodes, scan electrodes,sustain electrodes, and panel capacitors each formed between theaddress, scan, and sustain electrodes, includes: a first switch having afirst end coupled to a first power source for supplying a first voltage;a first diode coupled between a second power source for supplying asecond voltage and a second end of the first switch; a second switchcoupled between the panel capacitor and a point where the first switchand the first diode meet; an inductor and a third switch coupled inseries between the second power source and the point where the firstswitch and the first diode meet; a second diode coupled between a pointwhere the inductor and the third switch meet and a point where thesecond switch and the panel capacitor meet; and a third diode coupledbetween the first power source and the point where the second switch andthe panel capacitor meet.

In still another aspect of the present invention, a device for driving aPDP, the PDP having a plurality of address electrodes, scan electrodes,sustain electrodes, and panel capacitors each formed between theaddress, scan, and sustain electrodes, includes: a discharge unit,including a first inductor coupled to the panel capacitor, for storing afirst energy in the first inductor using the current in a firstdirection while the voltage at the panel capacitor maintains a firstvoltage, using the first energy and the resonance between the panelcapacitor and the first inductor to reduce the voltage at the panelcapacitor to a second voltage, and recovering the energy remaining inthe first inductor while maintaining the voltage at the panel capacitorto be the second voltage; and a charge unit, including a second inductorcoupled to the panel capacitor, for storing a second energy in thesecond inductor using the current in a second direction while thevoltage at the panel capacitor maintains the second voltage, using thesecond energy and the resonance between the panel capacitor and thesecond inductor to raise the voltage at the panel capacitor to the firstvoltage, and recovering the energy remaining in the second inductorwhile maintaining the voltage at the panel capacitor to be the firstvoltage.

In still yet another aspect of the present invention, a device fordriving a PDP, the PDP having a plurality of address electrodes, scanelectrodes, sustain electrodes, and panel capacitors each formed betweenthe address, scan, and sustain electrodes, includes: an inductor coupledto the panel capacitor; and a freewheeling unit for temporarilyfreewheeling the current flowing to the inductor, wherein energy isstored in the inductor while the voltage at the panel capacitormaintains a first voltage, the energy and the resonance between thepanel capacitor and the inductor are used to change the voltage at thepanel capacitor to a second voltage, and the energy freewheeled andcontinuously stored in the inductor during the maintaining of the secondvoltage is used to change the voltage at the panel capacitor to thefirst voltage.

In still yet another aspect of the present invention, a device fordriving a PDP, the PDP having a plurality of address electrodes, scanelectrodes, sustain electrodes, and panel capacitors each formed betweenthe address, scan, and sustain electrodes, includes: first and secondinductors coupled to the panel capacitor; first and second signal linesfor respectively transmitting first and second voltages; a capacitor forcharging a third voltage; a first current path formed between the firstsignal line and the capacitor so that a current in the first directionis supplied to the first inductor to store a first energy, while thevoltage at the panel capacitor is maintained to be the first voltage; asecond current path for generating resonance between the first inductorand the panel capacitor, and using the first energy and the resonance toreduce the voltage at the panel capacitor to a second voltage, while thefirst energy is stored in the first inductor; a third current path forrecovering the energy remaining in the first inductor while the voltageat the panel capacitor is changed to the second voltage; a fourthcurrent path formed between the capacitor and the second signal line sothat a current in the second direction opposite the first direction maybe supplied to the second inductor to store a second energy, while thevoltage at the panel capacitor is maintained to be the second voltage; afifth current path for generating resonance between the second inductorand the panel capacitor, and using the second energy and the resonanceto increase the voltage at the panel capacitor to the first voltage,while the second energy is stored in the second inductor; and a sixthcurrent path for recovering the energy remaining in the second inductorwhile the voltage at the panel capacitor is changed to the firstvoltage.

In still yet another aspect of the present invention, a device fordriving a PDP, the PDP having a plurality of address electrodes, scanelectrodes, sustain electrodes, and panel capacitors each formed betweenthe address, scan, and sustain electrodes, includes: an inductor coupledto the panel capacitor; first and second signal lines for transmittingfirst and second voltages; a first current path formed between the firstand the second signal lines so that the current may be supplied to theinductor to store a first energy, while the voltage at the panelcapacitor is maintained to be the first voltage; a second current pathfor generating resonance between the inductor and the panel capacitorwhile the first energy is stored in the inductor, and using the firstenergy and the resonance to reduce the voltage at the panel capacitor toa second voltage; at least one third current path for freewheeling thecurrent flowing to the inductor so as to maintain the second energyremaining in the inductor, while the voltage at the panel capacitor ischanged to the second voltage; a fourth current path for generatingresonance between the inductor and the panel capacitor while the currentflowing to the inductor is freewheeled, and using the second energy andthe resonance to increase the voltage at the panel capacitor to thefirst voltage; and a fifth current path for recovering the energyremaining in the inductor while the voltage at the panel capacitor ischanged to the first voltage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of a PDP according to an embodiment ofthe present invention.

FIG. 2 shows a circuit diagram of a PDP driving circuit according to afirst embodiment of the present invention.

FIGS. 3A through 3E show current paths of respective modes in thedriving circuit according to a first embodiment of the presentinvention.

FIG. 4 shows a driving timing diagram of the driving circuit accordingto a first embodiment of the present invention.

FIG. 5 shows a circuit diagram of a PDP driving circuit according to asecond embodiment of the present invention.

FIGS. 6A through 6E show current paths of respective modes in thedriving circuit according to a second embodiment of the presentinvention.

FIG. 7 shows a driving timing diagram of the driving circuit accordingto a second embodiment of the present invention.

FIG. 8 shows a circuit diagram of a PDP driving circuit according to athird embodiment of the present invention.

FIGS. 9A through 9E show current paths of respective modes in thedriving circuit according to a third embodiment of the presentinvention.

FIG. 10 shows a driving timing diagram of the driving circuit accordingto a third embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 shows a PDP according to an embodiment of the present invention.

As shown, the PDP includes plasma panel 100, address driver 200,scan/sustain driver 300, and controller 400.

Plasma panel 100 includes: a plurality of address electrodes A1 throughAm arranged in the column direction; a plurality of scan electrodes Y1through Yn arranged in the row direction; and a plurality of sustainelectrodes X1 through Xn alternately arranged with scan electrodes Y1through Yn in the row direction. Address driver 200 receives an addressdriving control signal from controller 400, and supplies a display datasignal for selecting a desired discharge cell to each address electrode.Scan/sustain driver 300 receives a sustain-discharge control signal fromcontroller 400, and alternately inputs sustain-discharge voltages to thescan electrodes and the sustain electrodes to thereby performsustain-discharge on the selected discharge cells. Address driver 200and scan/sustain driver 300 respectively include a driving circuit(i.e., a power recovery circuit) for recovering and using reactivepower. Controller 400 receives external image signals, generates addressdriving control signals and sustain-discharge control signals, andrespectively supplies them to address driver 200 and scan/sustain driver300.

With reference to FIGS. 2 through 4, driving circuit 210 of addressdriver 200 according to a first embodiment of the present invention willnow be described in detail.

FIG. 2 shows a circuit diagram of driving circuit 210 according to thefirst embodiment of the present invention, FIGS. 3A through 3E showcurrent paths of respective modes in driving circuit 210 according tothe first embodiment of the present invention, and FIG. 4 shows adriving timing diagram of driving circuit 210 according to the firstembodiment of the present invention.

As shown in FIG. 2, driving circuit 210 includes address unit 212 andcharge/discharge unit 214. Address unit 212 is coupled to ground andpower source Va for supplying voltage Va, and it includes addressswitches AH and AL each having a body diode. Voltage Va represents anaddress voltage for performing addressing. Panel capacitor Cp isprovided to a point where address switches AH and AL meet. A switchingoperation by address switches AH and AL supplies address voltage Va orground voltage to panel capacitor Cp. A plurality of address units 212is respectively coupled to a plurality of address electrodes A1 throughAm, and address voltage Va is supplied to the address electrodes coupledto address units 212 that have turned-on switch AH.

Charge/discharge unit 214 includes switches M1, M2, M3, and M4, boostinginductors L1 and L2, power recovery switches Ma and Mb, and capacitorsCr1 and Cr2. Switches M1 and M2 are coupled in series between powersource Va and ground, and switches M3 and M4 are coupled in seriesbetween power source Va and ground, differing from the path of switchesM1 and M2. Diodes D1 and D2 for respectively establishing a current pathsupplied to panel capacitor Cp and a current path recovered from panelcapacitor Cp may be provided between switches M1 and M2, and betweenswitches M3 and M4.

Boosting inductor L1 is provided between power recovery switch Ma and apoint where switches M1 and M2 meet, and boosting inductor L2 isprovided between power recovery switch Mb and a point where switches M3and M4 meet. Capacitors Cr1 and Cr2 are coupled in series between powersource Va and ground, and power recovery switches Ma and Mb are coupledto a point provided between capacitors Cr1 and Cr2.

Switches AH, AL, M1, M2, M3, M4, Ma, and Mb are denoted as MOSFETs inFIG. 2, but without being restricted this, any switches that performfunctions identical or similar to them may be applied.

Referring to FIGS. 3A through 3E and 4, a PDP driving method accordingto the first embodiment of the present invention will be described.

In the first embodiment, it is assumed that switches AH and M1 areturned on before the “mode 1” starts, respective voltages V1 and V2(V2=Va−V1) are charged to capacitors Cr1 and Cr2, and inductances atinductors L1 and L2 are respectively set to be L1 and L2.

(1) Mode 1 (t0 through t1)

Referring to FIG. 3A and an interval (t0 through t1) of FIG. 4, anoperation of mode 1 will be described.

In the “mode 1” interval (t0 through t1), switches M3 and Mb are turnedon while switches AH and M1 are turned on. As shown in FIG. 3A, whenswitches AH and M1 are turned on, current path 30 is formed in order ofswitch M1, switch AH, and panel capacitor Cp, and accordingly, addressvoltage Va is charged to panel capacitor Cp. Here, when switches M3 andMb are turned on, current path 31 is formed in order of switch M3,inductor L2, switch Mb, and capacitor Cr1. As shown in FIG. 4, currentIL2 that flows to inductor L2 has a gradient of (Va−V1)/L2 according tocurrent path 31, and linearly increases to store energy in inductor L2.

(2) Mode 2 (t1 through t2)

Referring to FIG. 3B and an interval (t1 through t2) of FIG. 4, anoperation of mode 2 will be described.

In the “mode 2” interval (t1 through t2), switches AH, M1, and M3 areturned off while switch Mb is turned on. As shown in FIG. 3B, currentpath 32 is then formed in order of panel capacitor Cp, a body diode ofswitch AH, inductor L2, switch Mb, and capacitor Cr1. In this instance,a resonance current flows due to inductor L2 and panel capacitor Cp, andaccordingly, voltage Vp at panel capacitor Cp falls to ground voltagefrom address voltage Va.

A process for discharging the voltage charged to the panel capacitor mayquickly proceed because of the energy stored in inductor L2. Namely, thefalling time (t2–t1) of voltage Vp at panel capacitor Cp reduces. Also,in the actual case of including a parasitic component of a circuit,voltage Vp at panel capacitor Cp may completely reduce to ground voltagedue to the energy stored in inductor L2.

(3) Mode 3 (t2 through t3)

Referring to FIG. 3C and an interval (t2 through t3) of FIG. 4, anoperation of mode 3 will be described.

In the “mode 3” interval (t2 through t3), switches M4 and AL aresequentially turned on while switch Mb is turned on.

When voltage Vp at panel capacitor Cp becomes ground voltage at t=t2,the body diode of switch M4 conducts. In this instance, when switch M4is turned on, the voltage between a drain and a source at switch M4 isturned on from the zero-voltage state. That is, since switch M4 performszero-voltage switching, no turning-on switching loss of switch M4 isgenerated. Also, switch M4 may perform zero-voltage switching because ofthe energy stored in inductor L2 when switch M4 has a parasiticcomponent of the circuit.

As shown in FIG. 3C, when switch M4 is turned on, current path 33 isformed in order of panel capacitor Cp, the body diode of switch AH, andswitch M4, and accordingly, voltage Vp at panel capacitor Cp issustained to be ground voltage. Also, when switch AL is turned on,current path 34 is formed in order of panel capacitor Cp and switch AL,and accordingly, voltage Vp at panel capacitor Cp is sustained to beground voltage.

Further, current path 35 is formed in order of the body diode of switchM4, inductor L2, switch Mb, and capacitor Cr1. The current flowing toinductor L2 has a gradient of −V1/L2 and linearly reduces to zerobecause of current path 35. That is, the energy stored in inductor L2 isrecovered to capacitor Cr1 through switch Mb.

Next, when switches Ma and M2 are turned on while switches Mb, AL, andM4 are turned on, current path 36 is formed in order of capacitor Cr1,switch Ma, inductor L1, and switch M2, and the current flowing toinductor L1 has a gradient of V1/L1 and linearly increases because ofcurrent path 36 to thereby store energy in inductor L1.

Before the mode 3 is finished, switches Mb and AL are sequentiallyturned off, and switch AH is turned on.

(4) Mode 4 (t3 through t4)

Referring to FIG. 3D and the interval (t3 through t4) of FIG. 4, anoperation of “mode 4” will now be described.

In the “mode 4” interval (t3 through t4), switches M2 and M4 are turnedoff while switches AH and Ma are turned on. As shown in FIG. 3D, currentpath 37 is formed in order of capacitor Cr1, switch Ma, inductor L1,switch AH, and panel capacitor Cp. In this instance, since resonancecurrent flows because of inductor L1 and panel capacitor Cp, voltage Vpat panel capacitor Cp increases to address voltage Va from groundvoltage.

The process for charging the voltage to the panel capacitor may quicklyproceed due to the energy stored in inductor L1. That is, the risingtime (t4–t3) of voltage Vp at panel capacitor Cp reduces. Also, voltageVp at panel capacitor Cp may completely increase to address voltage Vabecause of the energy stored in inductor L1 when a parasitic componentof a circuit is provided.

(5) Mode 5 (t4 through t5)

In the “mode 5” (t4 through t5), switch M1 is turned on while switchesAH and Ma are turned on.

When voltage Vp at panel capacitor Cp reaches address voltage Va att=t4, the body diode of switch M1 conducts. In this instance, whenswitch M1 is turned on, the voltage between the drain and the source atswitch M1 is turned on from the zero-voltage state. That is, sinceswitch M1 performs zero-voltage switching, no turning-on switching lossby switch M1 is generated.

As shown in FIG. 3E, when switch M1 is turned on, current path 38 isformed in order of switch M1, switch AH, and panel capacitor Cp tothereby maintain voltage Vp at panel capacitor Cp to be address voltageVa. Also, another current path 39 is formed in order of switch Ma,inductor L1, the body diode of switch M1, and capacitor Cr2. Current IL1flowing to inductor L1 has a gradient of −V2/L1 and linearly reduces tozero because of current path 39. That is, the energy stored in inductorL1 is recovered to capacitor Cr2 through the body diode of switch M1.

According to the first embodiment of the present invention describedabove, the current is stored in the inductor in the modes 1 and 3 whichare prior to charging the voltage to panel capacitor Cp (Mode 4) anddischarging the same from panel capacitor Cp (Mode 2), and the storedenergy is used so that voltage Vp at panel capacitor Cp may quickly riseto address voltage Va or fall to ground voltage, and when a parasiticcomponent of the circuit is provided, voltage Vp may completely rise tothe address voltage or completely fall to ground voltage. Also, theenergy stored in the inductor may be recovered in the modes 3 and 5 andreused.

With reference to FIGS. 5, 6A through 6E, and 7, a driving circuit and aPDP driving method according to a second embodiment of the presentinvention will be described.

FIG. 5 shows a circuit diagram of a PDP driving circuit according to thesecond embodiment of the present invention, FIGS. 6A through 6E showcurrent paths of respective modes in the driving circuit according tothe second embodiment of the present invention, and FIG. 7 shows adriving timing diagram of the driving circuit according to the secondembodiment of the present invention.

As shown in FIG. 5, driving circuit 210 has a circuit identical withthat of the first embodiment excluding switches M2 and M3 shown in FIG.2.

In detail, switches M1 and M4 of charge/discharge unit 214 according tothe second embodiment are coupled in series between power source Va andground, and address unit 212 is coupled to a point where switches M1 andM4 meet. Inductor L1 is provided between power recovery switch Ma andthe point provided between switches M1 and M4, and inductor L2 isprovided between power recovery switch Mb and the point provided betweenswitches M1 and M4. Diodes D1 and D2 for respectively forming a currentpath may be further provided between inductor L1 and switch Ma, andbetween inductor L2 and switch Mb.

Referring to FIGS. 6A through 6E, and 7, a PDP driving method accordingto the second embodiment of the present invention will now be described.

In the second embodiment, it is assumed in the like manner of the firstembodiment that switches AH and M1 are turned on before the mode 1starts, and voltages V1 and V2 (=Va−V1) are charged to capacitors Cr1and Cr2.

(1) Mode 1 (t0 through t1)

In the “mode 1” interval (t0 through t1), switch Mb is turned on whileswitches AH and M1 are turned on. As shown in FIG. 6A, when switches AHand M1 are turned on, current path 60 is formed, and address voltage Vais charged to panel capacitor Cp. Here, when switch Mb is turned on,current path 61 is formed, and current IL2 that flows to inductor L2 hasa gradient of (Va−V1)/L2 and linearly increases to store energy ininductor L2.

(2) Mode 2 (t1 through t2)

In the “mode 2” interval (t1 through t2), switches AH and M1 are turnedoff while switch Mb is turned on. As shown in FIG. 6B, current path 62is then formed, and a resonance current flows due to inductor L2 andpanel capacitor Cp, and accordingly, voltage Vp at panel capacitor Cpfalls to ground voltage from address voltage Va.

(3) Mode 3 (t2 through t3)

In the “mode 3” interval (t2 through t3), switches M4 and AL aresequentially turned on while switch Mb is turned on. As shown in FIG.6C, current paths 63 and 64 are formed, and voltage Vp at panelcapacitor Cp is sustained to be ground voltage. Also, current path 65 isformed, current IL2 flowing to inductor L2 has a gradient of −V1/L2 andlinearly reduces to zero, and hence, the energy stored in inductor L2 isrecovered to capacitor Cr1 through switch Mb.

In this instance, since voltage Vp at panel capacitor Cp becomes groundvoltage, and switch M4 is turned on while the body diode of switch M4conducts, no turning-on switching loss by switch M4 is generated.

Next, when switch Ma is turned on while switches Mb, M4, and AL areturned on, current path 66 is formed, and the current flowing toinductor L1 has a gradient of V1/Ll and linearly increases to therebystore energy in inductor L1.

Before the mode 3 is finished, switches Mb and AL are sequentiallyturned off, and switch AH is turned on.

(4) Mode 4 (t3 through t4)

In the “mode 4” interval (t3 through t4), switch M4 is turned off whileswitches AH and Ma are turned on. As shown in FIG. 6D, current path 67is formed, and since resonance current flows because of inductor L1 andpanel capacitor Cp, voltage Vp at panel capacitor Cp rises to addressvoltage Va from ground voltage.

(5) Mode 5 (t4 through t5)

In the mode 5 (t4 through t5), switch M1 is turned on while switches AHand Ma are turned on. As shown in FIG. 6E, current path 68 is thenformed to thereby maintain voltage Vp at panel capacitor Cp to beaddress voltage Va.

In this instance, since voltage Vp at panel capacitor Cp becomes addressvoltage Va, and switch M1 is turned on while the body diode of switch M1conducts, no turning-on switching loss by switch M1 is generated.

Also, another current path 69 is formed, and current IL1 flowing toinductor L1 has a gradient of −V2/L1 and linearly reduces to zero. Thatis, the energy stored in inductor L1 is recovered to capacitor Cr2through the body diode of switch M1.

According to the second embodiment of the present invention describedabove, the current is stored in the inductor in the modes 1 and 3 whichare prior to charging the voltage to panel capacitor Cp (Mode 4) anddischarging the same from panel capacitor Cp (Mode 2), and the storedenergy is used so that voltage Vp at panel capacitor Cp may quickly riseto address voltage Va or fall to ground voltage, thereby reducing therising and falling time. Also, the energy stored in the inductor may berecovered in the modes 3 and 5 and reused.

A PDP address driving circuit is exemplified for the driving circuitaccording to the first and second embodiments, and a driving circuit ofan element having a capacitive load may also be used. For example, itmay be applied to a driving circuit of the sustain electrodes and adriving circuit of the scan electrodes of scan/sustain driver 300.

Different inductors are used so as to charge and discharge panelcapacitor Cp in the first and second embodiments, and a single inductormay be used to charge and discharge panel capacitor Cp. A thirdembodiment will be subsequently described referring to FIGS. 8, 9Athrough 9E, and 10.

FIG. 8 shows a circuit diagram of a PDP driving circuit according to thethird embodiment of the present invention, FIGS. 9A through 9E showcurrent paths of respective modes in the driving circuit according tothe third embodiment of the present invention, and FIG. 10 shows adriving timing diagram of the driving circuit according to the thirdembodiment of the present invention.

With reference to FIG. 8, driving circuit 210 of address driver 200according to the third embodiment of the present invention will now bedescribed.

As shown, driving circuit 210 includes address unit 212 andcharge/discharge unit 214. Since address unit 212 is matched with thatof the first embodiment, no corresponding description will be provided.

Charge/discharge unit 214 includes switches M1, M2, and M3, inductor L,freewheeling diodes D1 and D2, and recovery diode D3. Switch M1,inductor L, and switch M3 are coupled in series between power source Vaand ground, and diode D1 is coupled between ground and a point whereswitch M1 and inductor L meet.

Switch M2 is coupled between switch AH of address unit 212 and the pointwhere switch M1 and inductor L meet. Diode D2 is coupled between switchAH and a point where inductor L and switch M3 meet. Diode D3 is coupledbetween power source Va and a point where switches M2 and AH meet, andit recovers the current flowing to inductor L to power source Va.

In this instance, diode D4 for establishing a current path recoveredfrom panel capacitor Cp may be further provided between inductor L andswitch M3.

Referring to FIGS. 9A through 9E and 10, a PDP driving method accordingto the third embodiment will be described.

In the third embodiment, it is assumed that address voltage Va ischarged to panel capacitor Cp before the mode 1 starts, switch M1 andswitch AH of the address unit are turned on, and the inductance ofinductor L is set to be L.

(1) Mode 1 (t0 through t1)

Referring to FIG. 9A and an interval (t0 through t1) of FIG. 10, anoperation of mode 1 will be described.

In the “mode 1” interval (t0 through t1), switches M2 and M3 are turnedon while switches M1 and AH are turned on.

As shown in FIG. 9A, when switch M2 is turned on while switches M1 andAH are turned on, current path 91 is formed in order of switch Ml,switch M2, switch AH, and panel capacitor Cp, and accordingly, voltageVp at panel capacitor Cp maintains address voltage Va. Also, when switchM3 is turned on while switch M1 is turned on, current path 92 is formedin order of switch M1, inductor L, diode D4, and switch M3. Current ILthat flows to inductor L has a gradient of Va/L according to currentpath 91, and linearly increases to thereby store energy in inductor L.

(2) Mode 2 (t1 through t2)

Referring to FIG. 9B and an interval (t1 through t2) of FIG. 10, anoperation of mode 2 will be described.

In the “mode 2” interval (t1 through t2), switch M1 is turned off whileswitches AH, M2, and M3 are turned on. As shown in FIG. 9B, current path93 is then formed in order of panel capacitor Cp, switch AH, switch M2,inductor L, diode D4, and switch M3. In this instance, an LC resonancecurrent flows due to inductor L and panel capacitor Cp, and accordingly,voltage Vp at panel capacitor Cp falls to ground voltage from addressvoltage Va, and current IL that flows to inductor L continuouslyincreases.

A process for recovering the voltage charged to panel capacitor Cp mayquickly proceed because of the energy stored in inductor L in mode 1.Namely, since the falling time (t2–t1) of voltage Vp at panel capacitorCp reduces, fast address recovery is possible. Also, in the actual caseof including a parasitic component of a circuit, voltage Vp at panelcapacitor Cp may completely reduce to ground voltage due to the energystored in inductor L.

(3) Mode 3 (t2 through t3)

Referring to FIG. 9C and an interval (t2 through t3) of FIG. 10, anoperation of mode 3 will be described.

In the “mode 3” interval (t2 through t3), switch AH is turned off andswitch AL is turned on while switches M2 and M3 are turned on.

When switch AH is turned off while switches M2 and M3 are turned on, thecurrent flowing to inductor L freewheels to current path 94 in order ofinductor L, diode D4, switch M3, and diode D1, and current path 95 inorder of inductor L, diode D2, and switch M2 according to freewheelingdiodes D1 and D2. Because of the above-noted freewheeling, current ILflowing to inductor L may continuously maintain a predetermined value asshown in FIG. 10.

When switch AL is turned on, current path 96 is formed in order of panelcapacitor Cp and switch AL, and accordingly, voltage Vp at panelcapacitor Cp is maintained to be ground voltage.

Switch AL is turned off before the mode 3 is finished.

(4) Mode 4 (t3 through t4)

Referring to FIG. 9D and the interval (t3 through t4) of FIG. 10, anoperation of “mode 4” will now be described.

In the “mode 4” interval (t3 through t4), switches M2 and M3 are turnedoff and switch AH is turned on, and as shown in FIG. 9D, current path 97is formed in order of diode D1, inductor L, diode D2, switch AH, andpanel capacitor Cp.

Since resonance current flows on current path 97 because of inductor Land panel capacitor Cp, voltage Vp at panel capacitor Cp rises toaddress voltage Va from ground voltage. The process for charging thevoltage to panel capacitor Cp may quickly proceed due to the energystored in inductor L. That is, the rising time (t4–t3) of voltage Vp atpanel capacitor Cp reduces. Also, voltage Vp at panel capacitor Cp maycompletely increase to address voltage Va because of the energy storedin inductor L when a parasitic component of a circuit is provided.

When voltage Vp at panel capacitor Cp is charged up to address voltageVa, current path 98 in order of diode D1, inductor L, diode D2, anddiode D3 is formed. Current IL flowing to inductor L is recovered topower and reduced to zero because of current path 98.

(5) Mode 5 (t4 through t5)

In the “mode 5” (t4 through t5), switch M1 is turned on while switchesAH is turned on. As shown in FIG. 9E, current path 99 is then formed inorder of switch M1, body diode of switch M2, switch AH, and panelcapacitor Cp to thereby maintain voltage Vp at panel capacitor Cp to beaddress voltage Va.

After this, the process of mode 1 through mode 5 is repeated, and hence,voltage Vp at panel capacitor Cp is repeatedly switched between addressvoltage Va and ground voltage.

According to the third embodiment of the present invention describedabove, voltage Vp at panel capacitor Cp may quickly rise to addressvoltage Va or fall to ground voltage by storing the current in theinductor and using the stored energy, and when a parasitic component ofthe circuit is provided, voltage Vp may completely rise to the addressvoltage or completely fall to ground voltage.

While this invention has been described in connection with what ispresently considered to be the most practical embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A device for driving a plasma display panel having a plurality ofaddress electrodes, scan electrodes, sustain electrodes, and panelcapacitors each formed between the address, scan, and sustainelectrodes, comprising: first and second inductors coupled to the panelcapacitor; first and second signal lines for respectively transmittingfirst and second voltages; a capacitor for charging a third voltage; afirst current path formed between the first signal line and thecapacitor so that a current in the first direction is supplied to thefirst inductor to store a first energy, while the voltage at the panelcapacitor is maintained to be the first voltage; a second current pathfor generating resonance between the first inductor and the panelcapacitor, and using the first energy and the resonance to reduce thevoltage at the panel capacitor to the second voltage, while the firstenergy is stored in the first inductor; a third current path forrecovering the energy remaining in the first inductor while the voltageat the panel capacitor is changed to the second voltage; a fourthcurrent path formed between the capacitor and the second signal line sothat a current in the second direction opposite the first direction maybe supplied to the second inductor to store a second energy, while thevoltage at the panel capacitor is maintained to be the second voltage; afifth current path for generating resonance between the second inductorand the panel capacitor, and using the second energy and the resonanceto increase the voltage at the panel capacitor to the first voltage,while the second energy is stored in the second inductor; and a sixthcurrent path for recovering the energy remaining in the second inductorwhile the voltage at the panel capacitor is changed to the firstvoltage.
 2. The device of claim 1, wherein the first signal line iscoupled to the panel capacitor so as to maintain the voltage at thepanel capacitor to be the first voltage, and the second signal line iscoupled to the panel capacitor so as to maintain the voltage at thepanel capacitor to be the second voltage.
 3. The device of claim 1,further comprising: a first switch coupled between the second signalline and a point where the panel capacitor and the first inductor meet,and having a body diode; and a second switch coupled between the firstsignal line and a point where the panel capacitor and the secondinductor meet, and having a body diode, wherein the first switch isturned on when the voltage at the panel capacitor becomes the secondvoltage, and the second switch is turned on when the voltage at thepanel capacitor becomes the first voltage.
 4. The device of claim 3,wherein the third and the sixth current paths are formed through thebody diodes of the first and the second switches.
 5. A device fordriving a plasma display panel having a plurality of address electrodes,scan electrodes, sustain electrodes, and panel capacitors each formedbetween the address, scan, and sustain electrodes, comprising: aninductor coupled to the panel capacitor; first and second signal linesfor transmitting first and second voltages; a first current path formedbetween the first and the second signal lines so that current may besupplied to the inductor to store a first energy, while the voltage atthe panel capacitor is maintained to be the first voltage; a secondcurrent path for generating resonance between the inductor and the panelcapacitor while the first energy is stored in the inductor, and usingthe first energy and the resonance to reduce the voltage at the panelcapacitor to the second voltage; at least one third current path forfreewheeling the current flowing to the inductor so as to maintain asecond energy remaining in the inductor, while the voltage at the panelcapacitor is changed to the second voltage; a fourth current path forgenerating resonance between the inductor and the panel capacitor whilecurrent flowing to the inductor is freewheeled, and using the secondenergy and the resonance to increase the voltage at the panel capacitorto the first voltage; and a fifth current path for recovering the energyremaining in the inductor while the voltage at the panel capacitor ischanged to the first voltage.
 6. The device of claim 5, furthercomprising: a first switch coupled between the first signal line and oneend of the inductor; a second switch coupled between the one end of theinductor and the panel capacitor; and a third switch coupled betweenanother end of the inductor and the second signal line, wherein thefirst current path is formed when the first and the third switches areturned on, and the second current path is formed when the second and thethird switches are turned on.
 7. The device of claim 6, furthercomprising: a first diode coupled between the one end of the inductorand the third switch; and a second diode coupled between the other endof the inductor and the second switch, wherein the third current path isformed when the second and the third switches are turned on while thesecond switch is decoupled from the panel capacitor, and it comprises acurrent path formed through the second switch and the first diode, and acurrent path formed through the second diode and the third switch. 8.The device of claim 7, further comprising a third diode formed betweenthe second diode and the first signal line, wherein the fourth currentpath is formed through the first diode, the inductor, and the seconddiode, and the fifth current path is formed through the first diode, theinductor, and the second and the third diodes, while the first throughthird switches are turned off.